Associative links between obesity and vitamin D levels as a risk factor for primary hyperparathyroidism

Abstract

To date, the fact and mechanisms of associative links between vitamin D deficiency and primary hyperparathyroidism have been established. In turn, the level of 25 (OH) D is influenced by climatic conditions and the presence of obesity.
 Objective — to determine the supply of vitamin D in patients with endocrine disorders living in the climate in Ukraine, and to assess the impact of obesity on vitamin D levels and the development of hypercalcemia (signs of primary hyperparathyroidism).
 Materials and methods. Body mass index (BMI), serum levels of Ca and vitamin D were assessed in 145 patients, hospitalized in the clinic of Institute of Endocrine Pathology named after V. Ya. Danilevsky NAMS of Ukraine for various endocrine pathologies. The frequency of vitamin insufficiency and vitamin D efficiency, hypercalcemia was analyzed in groups with and without obesity.
 Results. The proportion of obese in the general group was 33.8 %, among men — 28.57 %, among women — 35.04 % (p < 0.05). The level of Ca in the blood was 2.39 ± 0.02 mmol/L, high Ca level occurred in 16.55 %, and obesity — in 49 (33.49 %) patients. Against the background of obesity, the level of Ca was 2.42 ± 0.02, and in non-obese people — 2.38 ± 0.02 (p > 0.05). Average level of vitamin D in the blood in the general group was 22.95 ± 0.73 mg/ml and was probably lower in the individuals with obesity (20.95 ± 1.39 vs. 24.09 ± 0.81 mg/ml in groups without obesity, p < 0.05). Distribution of the disease by the degree of vitamin D provision showed that in a cohort with low security vitamin D and the presence of obesity subgroup with a deficiency of vitamin D (20 — 29 ng/ ml) was 1.5 times bigger as the similar subgroup without obesity.
 Conclusions. In the climatic conditions of Ukraine, the average level of vitamin D in patients with endocrine pathology is within its deficiency (22.95 ± 0.73 ng/ ml). The presence of obesity in patients with endocrine pathology is associated with a probably lower supply of vitamin D, almost 1.5 times bigger the subgroup with vitamin deficiency (< 20 ng/ ml). The combination of obesity and vitamin D deficiency should be considered as a risk factor for primary hyperparathyroidism in patients with endocrine pathology. Such patients need regular monitoring of blood levels of calcium and parathyroid hormone, as well as medical support for adequate supply of vitamin D.